Any time you search for something or someone on Facebook, your search information is automatically stored in your account's Activity Log. Although your search history is viewable only by you, clearing it can improve the speed at which Facebook runs on your computer or mobile device. Use the Clear Searches tool in your Activity Log to delete your Facebook search history.
Clear Entire Search History
Step 1: Click your name on the main menu along the top of the screen to load your Timeline.
Step 2: Click the View Activity Log button to open your account's Activity Log.
Step 3: Select More on the menu located along the left of the screen.
Step 4: Choose Search to display your Facebook search history.
Step 5: Click Clear Searches.
Step 6: Click Clear Searches on the pop-up dialog to confirm you want to delete your Facebook search history.
Remove Individual Searches
To remove an individual search from your Activity Log, click Search on your Activity Log menu as described above and locate the search you want to delete. Searches are listed chronologically, with the most recent displayed at the top of the list. Click the circle icon next to the search term and select Delete.
Clearing Search on Mobile Devices
If you're using the official Facebook app for iOS or Android devices, you can clear searches individually only from your Activity Log.
Open your profile in the Facebook app, swipe the tiles under your profile photo to the left and tap Activity Log. Select Filter, scroll down and tap Search. Locate the search you want to delete, touch the arrow located next to it and tap Remove. Repeat this process for each search you want to delete.